The 1873 does 70 base damage, with a delay of 0.9 seconds. Assuming we're talking two body shots, that's a time-to-kill of a little over 0.9 seconds.
The M14 EBR does 30 base damage, with a delay of 0.35 seconds. At four body shots, that's a time-to-kill of a little over 1.05 seconds.
Especially considering gmod's bad hitreg, I think the 1873 is actually very much in line with the rest of the DMR category. Rejected.